import 'dotenv/config';
import { createServer } from 'http';
const PORT = process.env.PORT;

const users = [
    { id:1, name: '张三' },
    { id:2, name: '李四' },
    { id:3, name: '王五' }
];

// Logger 中间件
const logger = (req, res, next) => {
    console.log(`${req.method} ${req.url}`);
    next(); // 调⽤下⼀个中间件
};  

const jsonMiddleware = (req, res, next) => {
        res.setHeader('Content-Type', 'application/json; charset=utf-8');
        next();
}
const getUsersHandler = (req, res) => {
    res.write(JSON.stringify(users));
    res.end();
   };

const getUserHandler = (req, res) => {
    const id = req.url.split('/')[3];
    const user = users.find(user => user.id == id);
    if(user) {
    res.write(JSON.stringify(user));
    } else {
    res.statusCode = 404;
    res.write(JSON.stringify({ message: '⽤户不存在' }));
    }
    res.end();
};
   
// 路由处理 404
const notFoundHandler = (req, res) => {
    res.statusCode = 404;
    res.write(JSON.stringify({ message: 'API不存在' 
   }));
    res.end();
};
// 路由处理 POST /api/users
const createUserHandler = (req, res) => {
    let body = '';
    // 监听'data'事件，逐块接收请求体的数据
    req.on('data', (chunk) => {
    body += chunk.toString();
    });
    // 数据接收完毕后，触发'end'事件
    req.on('end', () => {
    const user = JSON.parse(body); // 解析请求体中的JSON数据
    users.push(user); // 将解析出的⽤户添加到⽤户列表中
    res.statusCode = 201; // 设置响应状态码为201，表⽰创建成功
    res.write(JSON.stringify(user)); // 返回创建的⽤户数据
    res.end();
    });
};

const server = createServer((req,res) => {

    logger(req,res,() =>{
        jsonMiddleware(req,res,() => {
            if(req.url === '/api/users' && req.method === 'GET') {
                getUsersHandler(req,res);
            } else if(req.url.startsWith('api/users/') && req.method === 'GET'){
                getUsersHandler(req,res);
            }else if (req.url === 'api/users' && req.method === 'POST'){
                createUserHandler(req,res);
            } else {
                notFoundHandler(req,res);
            }
        })
    })
});


server.listen(PORT,() => {
    console.log(`服务器已启动,监听端口${PORT}`);
});